Transient early-childhood hyperkalaemia without salt wasting, pathophysiological approach of three cases.

Two types of early childhood hyperkalemia had been recognized, according to the presence or absence of urinary salt wasting. This condition was attributed to a maturation disorder of aldosterone receptors and is characterized by sustained hyperkalemia, hyperchloremic metabolic acidosis (MA) due to reduced ammonium urinary excretion and bicarbonate loss, and normal creatinine with growth delay. We present 3 patients of the type without salt wasting, which we will call transient early-childhood hyperkalemia (TECHH) without salt wasting, and discuss its physiopathology according to new insights into sodium and potassium handling by the aldosterone in distal nephron. In 3 children from 30 to 120-day-old admitted with bronchiolitis and growth delay hyperkalemia was found in routine laboratory. Further studies revealed a normal creatinine with inappropriately normal or low fractional excretion (FE) of potassium, accompanied by inadequately normal serum aldosterone and plasma renin activity for their higher plasma potassium levels, but without urine salt wasting. They also presented hyperchloremic MA with FE of bicarbonate 0.58%-2.2%, positive urinary anion gap during MA and normal ability to acidify the urine. Based on these findings a diagnosis of TECHH without salt wasting was made and they were treated sodium bicarbonate and hydrochlorothiazide with favorable response. The condition was transient in all cases leading to treatment discontinuation. Given that TECCH without salt wasting is a tubular disorder of transient nature with mild symptoms; it must be keep in mind in the differential diagnosis of hyperkalemia in young children.

Hiperpotasemia transitoria del lactante sin pérdida salina, enfoque fisiopatológico de tres casos / Transient early-childhood hyperkalemia without salt wasting, physiopathological approach of three cases

Se reconocen 2 variedades de hiperpotasemia temprana de la infancia (del inglés Early childhood hyperkalemia) según la presencia o no de pérdida salina urinaria. Se trata de una entidad atribuida a un desorden madurativo en los receptores de aldosterona caracterizada por hiperpotasemia, acidosis metabólica hiperclorémica por diminución de la eliminación de amonio y bicarbonaturia, y creatinina normal con retraso de crecimiento. Presentamos 3 pacientes de la forma con ausencia de pérdida salina, a la que denominaremos hiperpotasemia transitoria del lactante sin pérdida salina, y discutimos su fisiopatología con relación a los nuevos conocimientos en el manejo tubular del sodio y el potasio por la aldosterona. En 3 pacientes de entre 30 y 120 días de edad con bronquiolitis y retraso de crecimiento se encontró hiperpotasemia en laboratorio de rutina. Presentaban creatinina normal, excreción fraccionada de potasio disminuida o inapropiadamente normal junto a niveles de aldosterona y renina plasmática inadecuadamente normales para el estado de hiperpotasemia, pero sin pérdida salina. También cursaban con acidosis metabólica hiperclorémica con bicarbonaturia (excreción fraccionada de bicarbonato 0,58-2,2%), anión restante urinario positivo durante acidosis metabólica y capacidad normal para acidificar la orina. En base a estos hallazgos se diagnosticó hiperpotasemia transitoria del lactante sin pérdida salina y se trataron con bicarbonato de sodio e hidroclorotiazida con buena respuesta. El cuadro fue transitorio permitiendo la suspensión del tratamiento. Dado que la hiperpotasemia transitoria del lactante sin pérdida salina es un desorden tubular transitorio con síntomas leves debe tenerse presente en el diagnóstico diferencial de hiperpotasemia en niños pequeños. (AU)

Two types of early-childhood hyperkalemia had been recognized, according to the presence or absence of urinary salt wasting. This condition was attributed to a maturation disorder of aldosterone receptors and is characterized by sustained hyperkalemia, hyperchloremic metabolic acidosis due to reduced ammonium urinary excretion and bicarbonate loss, and normal creatinine with growth delay. We present three patients of the type without salt wasting, which we will call transient early-childhood hyperkalemia without salt wasting, and discuss its physiopathology according to new insights into sodium and potassium handling by the aldosterone in distal nephron. In three children from 30 to 120-day-old admitted with bronchiolitis and growth delay hyperkalemia was found in routine laboratory. Further studies revealed a normal creatinine with inappropriately normal or low fractional excretion of potassium, accompanied by inadequately normal serum aldosterone and plasma renin activity for their higher plasma potassium levels, but without urine salt wasting. They also presented hyperchloremic metabolic acidosis with fractional excretion of bicarbonate 0.58–2.2%, positive urinary anion gap during metabolic acidosis and normal ability to acidify the urine. Based on these findings a diagnosis of transient early-childhood hyperkalemia without salt wasting was made and they were treated sodium bicarbonate and hydrochlorothiazide with favorable response. The condition was transient in all cases leading to treatment discontinuation. Given that transient early-childhood hyperkalemia without salt wasting is a tubular disorder of transient nature with mild symptoms; it must be keep in mind in the differential diagnosis of hyperkalemia in young children. (AU)

Transient early-childhood hyperkalemia without salt wasting, physiopathological approach of three cases. / Hiperpotasemia transitoria del lactante sin pérdida salina, enfoque fisiopatológico de tres casos.

Two types of early-childhood hyperkalemia had been recognized, according to the presence or absence of urinary salt wasting. This condition was attributed to a maturation disorder of aldosterone receptors and is characterized by sustained hyperkalemia, hyperchloremic metabolic acidosis due to reduced ammonium urinary excretion and bicarbonate loss, and normal creatinine with growth delay. We present three patients of the type without salt wasting, which we will call transient early-childhood hyperkalemia without salt wasting, and discuss its physiopathology according to new insights into sodium and potassium handling by the aldosterone in distal nephron. In three children from 30 to 120-day-old admitted with bronchiolitis and growth delay hyperkalemia was found in routine laboratory. Further studies revealed a normal creatinine with inappropriately normal or low fractional excretion of potassium, accompanied by inadequately normal serum aldosterone and plasma renin activity for their higher plasma potassium levels, but without urine salt wasting. They also presented hyperchloremic metabolic acidosis with fractional excretion of bicarbonate 0.58-2.2%, positive urinary anion gap during metabolic acidosis and normal ability to acidify the urine. Based on these findings a diagnosis of transient early-childhood hyperkalemia without salt wasting was made and they were treated sodium bicarbonate and hydrochlorothiazide with favorable response. The condition was transient in all cases leading to treatment discontinuation. Given that transient early-childhood hyperkalemia without salt wasting is a tubular disorder of transient nature with mild symptoms; it must be keep in mind in the differential diagnosis of hyperkalemia in young children.

Prodromal Phase of Hemolytic Uremic Syndrome Related to Shiga Toxin-Producing Escherichia coli: The Wasted Time.

OBJECTIVES: This study aimed to evaluate practice patterns during prodromal phase of hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS). METHODS: Trajectories of children from first symptoms until STEC-HUS admitted consecutively at our center (period 2000-2017) were retrospectively reviewed. Early recommended practices include identification of STEC infections, antibiotics and antiperistaltic avoidance, and administration of anticipatory intravenous fluids; therefore, implementation and changes over time (before and after 2011) of such interventions were assessed. In addition, early management was correlated with acute disease outcomes. RESULTS: Of 172 patients, 98 (57%) had early consults, 75 of them visit the pediatric emergency department. Those seen with watery diarrhea (n = 74) were managed as outpatients, whereas 27 of the 45 assisted with bloody diarrhea were hospitalized for diagnosis other than STEC-HUS. Stool cultures were performed in 13.4% (23/172), 18% (31/172) received antibiotics, and 12.8% (22/172) received endovenous fluids; none received antiperistaltic agents. Shiga toxin-producing E. coli infection was proven in 4% (7/172) before HUS. Rate of cultured patients and treated with intravenous fluids remained unchanged over time (P = 0.13 and P = 0.48, respectively), whereas antibiotic prescription decreased from 42.8% to 16.6% (P = 0.005). Main acute outcomes (need for dialysis, pancreatic compromise, central nervous system involvement, and death) were similar (P > 0.05) regardless of whether they received antibiotics or intravenous fluids. CONCLUSIONS: During the diarrheal phase, 57% of patients consulted; three-quarters of them consulted to the pediatric emergency department. Shiga toxin-producing E. coli detection was poor, antibiotic use remained high, and anticipatory volume expansion was underused. These findings outline the critical need to improve the early management of STEC-HUS.

C3 levels and acute outcomes in Shiga toxin-related hemolytic uremic syndrome.

BACKGROUND: The correlation between complement activation and severity of hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS) has been examined in few studies, with conflicting results. We investigated whether C3 levels on admission are associated with worse acute outcomes. METHODS: Demographic, clinical, and laboratory variables were compared between dialyzed and non-dialyzed patients and between those with or without extrarenal complications. Univariate and multivariate analyses were performed; odds ratio (OR) and 95% confidence interval (95%CI) were calculated. C3 concentrations were correlated with dialysis length (Spearman test) and ROC curves with area under the curves (AUC) were calculated to identify C3 concentrations able to discriminate patients with dialysis requirements and complicated course. RESULTS: Among 49 children, 33 had normal and 16 had decreased C3 concentrations. Higher hemoglobin, lactic dehydrogenase, urea and creatinine and lower albumin, sodium, and C3 and C4 concentrations at admission were associated with dialysis requirement; only creatinine remained significant (p = 0.03, OR 2.1, 95%CI 1.34-2.7) by multivariate analysis. Patients with a complicated course presented higher leukocyte count, hemoglobin and lactic dehydrogenase and lower albumin, sodium, and C3 and C4. In the multivariate analysis, leukocyte count (p = 0.02, OR 2.6, 95%CI 1.4-4.3) and C3 concentration (p = 0.039, OR 1.7, 95%CI 1.1-2.73) were independently associated with a complicated disease. C3 levels correlated with dialysis length (r = - 0.42, p = 0.002); nevertheless, they were unable to discriminate dialysis requirement (AUC = 0.25, 95%CI 0.11-0.38) and extrarenal complications (AUC = 0.24, 95%CI 0.11-0.4). CONCLUSIONS: Our study suggests that decreased C3 levels at admission are associated with a more complicated STEC-HUS episode.

Correction to: C3 levels and acute outcomes in Shiga toxin-related hemolytic uremic syndrome.

Due to an unfortunate error during the processing of the article, the spelling of the second author name was incorrect.

[Maillard reaction. Pathogenic effects]. / Reacción de Maillard. Efectos patogénicos.

Certain organoleptic modifications by way of processing and cooking foods at high temperatures in dry heat, make them especially appetizing and objects of addiction. It results from Maillard reaction, or glycation, consisting of the non-enzymatic union between carbonyl groups, mainly from reducing sugars as glucose and fructose, with the amino group of proteins and nucleic acids. In addition to physical changes, also the chemical structure and function of these compounds are changed. Besides exogenous glycation generated during the cooking of foods, recently in situ glycation has been reported in the intestinal lumen during digestion, when certain non-glycated foods are combined with fructose at the time of ingestion. In addition, endogenous glycation, which correlates in the extracellular mainly with blood glucose and in the intracellular with glycolysis metabolites and fructose, is specially significant. Since the 70s, with the frequent sucrose replacement by fructose, much more reactive than glucose, the presence of glycation products in processed foods and soft drinks increased.Pathogenic effects of these compounds, also called glycotoxins, are known to contribute to oxidative stress and inflammation. This increases progression of chronic diseases, well documented in diabetes, renal insuficiency, cardiovascular disease and aging process, and are being explore d in many other chronic diseases as neurodegenerative disorders and early aging. Based on the knowledge achieved so far, measures to preserve health are described by attending ways of cooking and processing foods, besides recommendations for life habits and antioxidants dietary intakes for inhibition or antagonism on glycotoxins.

La cocción de los alimentos a altas temperaturas en calor seco, produce ciertas modificaciones organolépticas que los hace especialmente apetecibles y objetos de adicción. Esto es resultado de la reacción de Maillard, o glicación, que se produce por unión no enzimática del grupo carbonilo, de azúcares reductores como glucosa y fructosa, con el grupo amino de proteínas y ácidos nucleicos. Junto a los cambios físicos, cambia la estructura química y la función de estos aductos, denominados también glicotoxinas. Además de la glicación exógena, generada durante la cocción de los alimentos, recientemente ha sido referida la glicación in situ, en la luz intestinal, durante la digestión, cuando determinados alimentos no glicados se combinan en el momento de su ingestión. A esto se agrega la glicación endógena extracelular relacionada con la glucosa sanguínea y la intracelular, con metabolitos de la glucólisis y de la fructosa. Desde la década del 70, con el remplazo en gran medida de la sacarosa por fructosa, significativamente más reactiva que la glucosa, aumentó la presencia de productos de glicación en alimentos procesados y bebidas gaseosas. Están documentados sus efectos patogénicos como contribuyentes al estrés oxidativo y a la inflamación, especialmente en diabetes, insuficiencia renal y enfermedad cardiovascular y están siendo explorados en otras enfermedades crónicas, como procesos neurodegenerativos y envejecimiento temprano. Se describen medidas para preservar la salud, atendiendo medios de cocción y procesamiento de los alimentos y recomendaciones sobre hábitos de vida e ingesta de antioxidantes para acción inhibitoria o antagónica sobre las glicotoxinas.

Reacción de Maillard: Efectos patogénicos / Maillard reaction. Pathogenic effects

La cocción de los alimentos a altas temperaturas en calor seco, produce ciertas modificaciones organolépticas que los hace especialmente apetecibles y objetos de adicción. Esto es resultado de la reacción de Maillard, o glicación, que se produce por unión no enzimática del grupo carbonilo, de azúcares reductores como glucosa y fructosa, con el grupo amino de proteínas y ácidos nucleicos. Junto a los cambios físicos, cambia la estructura química y la función de estos aductos, denominados también glicotoxinas. Además de la glicación exógena, generada durante la cocción de los alimentos, recientemente ha sido referida la glicación in situ, en la luz intestinal, durante la digestión, cuando determinados alimentos no glicados se combinan en el momento de su ingestión. A esto se agrega la glicación endógena extracelular relacionada con la glucosa sanguínea y la intracelular, con metabolitos de la glucólisis y de la fructosa. Desde la década del 70, con el remplazo en gran medida de la sacarosa por fructosa, significativamente más reactiva que la glucosa, aumentó la presencia de productos de glicación en alimentos procesados y bebidas gaseosas. Están documentados sus efectos patogénicos como contribuyentes al estrés oxidativo y a la inflamación, especialmente en diabetes, insuficiencia renal y enfermedad cardiovascular y están siendo explorados en otras enfermedades crónicas, como procesos neurodegenerativos y envejecimiento temprano. Se describen medidas para preservar la salud, atendiendo medios de cocción y procesamiento de los alimentos y recomendaciones sobre hábitos de vida e ingesta de antioxidantes para acción inhibitoria o antagónica sobre las glicotoxinas.

Certain organoleptic modifications by way of processing and cooking foods at high temperatures in dry heat, make them especially appetizing and objects of addiction. It results from Maillard reaction, or glycation, consisting of the non-enzymatic union between carbonyl groups, mainly from reducing sugars as glucose and fructose, with the amino group of proteins and nucleic acids. In addition to physical changes, also the chemical structure and function of these compounds are changed. Besides exogenous glycation generated during the cooking of foods, recently in situ glycation has been reported in the intestinal lumen during digestion, when certain non-glycated foods are combined with fructose at the time of ingestion. In addition, endogenous glycation, which correlates in the extracellular mainly with blood glucose and in the intracellular with glycolysis metabolites and fructose, is specially significant. Since the 70s, with the frequent sucrose replacement by fructose, much more reactive than glucose, the presence of glycation products in processed foods and soft drinks increased.Pathogenic effects of these compounds, also called glycotoxins, are known to contribute to oxidative stress and inflammation. This increases progression of chronic diseases, well documented in diabetes, renal insuficiency, cardiovascular disease and aging process, and are being explore d in many other chronic diseases as neurodegenerative disorders and early aging. Based on the knowledge achieved so far, measures to preserve health are described by attending ways of cooking and processing foods, besides recommendations for life habits and antioxidants dietary intakes for inhibition or antagonism on glycotoxins.

Blood urea nitrogen to serum creatinine ratio as a prognostic factor in diarrhea-associated hemolytic uremic syndrome: a validation study.

Identifying those children with complicated forms of diarrhea-associated hemolytic uremic syndrome (D+HUS) on admission can optimize their management. Recently, the blood urea nitrogen to serum creatinine ratio (BCR) at admission has been proposed as a novel and accurate predictor of complicated clinical outcome in D+HUS; therefore, we performed this retrospective study aimed to validate such observation in a larger series of patients. A complicated course was defined as developing one or more of the following: severe neurological or bowel injury, pancreatitis, cardiac or pulmonary involvement, hemodynamic instability, hemorrhage, and death. Data from 161 children were reviewed, 50 of them with a complicated disease including five deaths. Those with worse evolution presented a lower admission BCR than those with good outcome (22.5 vs. 30.8; p = 0.005). BCR at admission showed a limited ability to identify children at risk of a complicated course, with an AUC of 0.63 (95% CI 0.58-0.71) and an optimal cutoff point of ≤ 26.7, which achieves a sensitivity of 70% (95% CI 55.2-81.7) and a specificity of 56.7% (95% CI 47-66). CONCLUSION: In this validation study, the BCR at admission provided a limited value to predict severe forms of D+HUS. What is Known: • BCR at admission has been proposed as an accurate predictor of complicated clinical course in children with D+HUS. What is New: • In a larger series of children with D+HUS, we were unable to confirm the usefulness of the admission BCR to early identify those at risk of complicated forms of the disease. • Further research is warranted to improve the optimal detection of these high-risk patients.

Síndrome urémico hemolítico asociado a diarrea sin trombocitopenia / Postdiarrhoeal haemolytic uraemic syndrome without thrombocytopenia

Antecedentes: La presencia de trombocitopenia es una marca distintiva del síndrome urémico hemolítico asociado a diarrea (SUH D+); sin embargo, puede ser transitoria y, por lo tanto, no ser detectada. Existe limitada información sobre la prevalencia y el curso de la enfermedad en niños con SUH D+ sin trombocitopenia. Objetivo: Determinar la prevalencia de SUH D+ sin trombocitopenia y describir las características clínicas de una serie de niños con esta particularidad. Pacientes y métodos: Fueron revisadas las historias clínicas de los pacientes con SUH D+ internados entre 2000 y 2016 para identificar a aquellos sin trombocitopenia (>150.000mm3). De los casos seleccionados se recolectaron las variables demográficas, clínicas y de laboratorio, las cuales fueron analizadas descriptivamente. Resultados: De 161 pacientes internados durante el periodo de estudio se identificaron 9 sin trombocitopenia (5,6%). La mediana de la edad al diagnóstico fue de 17 meses (7-32) y la de la duración del periodo prodrómico, de 15 días (7-21). Ocho pacientes mantuvieron diuresis normal y uno requirió diálisis. Ningún paciente presentó compromiso extrarrenal severo y/o hipertensión arterial. Conclusiones: La prevalencia de SUH D+ sin trombocitopenia fue del 5,6% y la mayoría de los casos fueron leves; sin embargo, el requerimiento de diálisis en uno de ellos señala que la normalización del recuento de plaquetas no siempre es un marcador preciso de resolución de la enfermedad. Nuestros resultados también confirman que el momento de presentación de los pacientes con SUH D+ sin trombocitopenia está usualmente alejado de los primeros síntomas intestinales, por lo que es necesario un alto índice de sospecha diagnóstica (AU)

Background: Thrombocytopenia is a hallmark of postdiarrhoeal haemolytic uraemic syndrome (D+ HUS), although it can be transient and therefore undetected. There is scarce information regarding the prevalence and the course of the disease in children with D+ HUS without thrombocytopenia. Objective: To determine the prevalence of D+ HUS without thrombocytopenia and to describe the clinical characteristics of a series of children with this condition. Patients and methods: The medical records of patients with D+ HUS hospitalised between 2000 and 2016 were reviewed to identify those without thrombocytopenia (>150,000mm3). Demographic, clinical and laboratory parameters of the selected cases were collected and descriptively analysed. Results: Nine cases (5.6%) without thrombocytopenia were identified among 161 patients hospitalised during the study period. Median age at diagnosis was 17 months (7-32) and median prodromal symptom duration was 15 days (7-21). Eight patients maintained normal urine output while the remaining one required dialysis. No patient presented with severe extrarenal compromise and/or hypertension. Conclusions: The prevalence of non-thrombocytopenic D+ HUS was 5.6% and most cases occurred with mild forms of the disease; however, the need for dialysis in one of them indicated that normalisation of platelet count is not always an accurate marker for disease remittance. Our results also confirm that the time of onset of D+ HUS in patients without thrombocytopenia is usually delayed with respect to the initial intestinal symptoms; thus, heightened diagnostic suspicion is necessary (AU)

Postdiarrhoeal haemolytic uraemic syndrome without thrombocytopenia. / Síndrome urémico hemolítico asociado a diarrea sin trombocitopenia.

BACKGROUND: Thrombocytopenia is a hallmark of postdiarrhoeal haemolytic uraemic syndrome (D+ HUS), although it can be transient and therefore undetected. There is scarce information regarding the prevalence and the course of the disease in children with D+ HUS without thrombocytopenia. OBJECTIVE: To determine the prevalence of D+ HUS without thrombocytopenia and to describe the clinical characteristics of a series of children with this condition. PATIENTS AND METHODS: The medical records of patients with D+ HUS hospitalised between 2000 and 2016 were reviewed to identify those without thrombocytopenia (>150,000mm3). Demographic, clinical and laboratory parameters of the selected cases were collected and descriptively analysed. RESULTS: Nine cases (5.6%) without thrombocytopenia were identified among 161 patients hospitalised during the study period. Median age at diagnosis was 17 months (7-32) and median prodromal symptom duration was 15 days (7-21). Eight patients maintained normal urine output while the remaining one required dialysis. No patient presented with severe extrarenal compromise and/or hypertension. CONCLUSIONS: The prevalence of non-thrombocytopenic D+ HUS was 5.6% and most cases occurred with mild forms of the disease; however, the need for dialysis in one of them indicated that normalisation of platelet count is not always an accurate marker for disease remittance. Our results also confirm that the time of onset of D+ HUS in patients without thrombocytopenia is usually delayed with respect to the initial intestinal symptoms; thus, heightened diagnostic suspicion is necessary.

Early erythropoietin in post-diarrheal hemolytic uremic syndrome: a case-control study.

BACKGROUND: Although erythropoietin (EPO) deficiency has been reported in children with post-diarrheal hemolytic uremic syndrome (D + HUS), very limited clinical data on EPO use in this disease are currently available. In this case-control study we examined whether EPO administration would reduce the number of red blood cell (RBC) transfusions in D + HUS patients under our care. METHODS: Data from children treated exclusively with RBC transfusions (controls; n = 21) were retrospectively compared with data on those who also received EPO for the treatment of anemia (cases; n = 21). RESULTS: Both patient groups were similar in age (p = 0.9), gender (p = 0.12), weight (p = 1.00) and height (p = 0.66). Acute phase severity was also comparable, as inferred by the need for dialysis (p = 0.74), the duration of dialysis (p = 0.3), length of hospitalization (p = 0.81), presence of severe bowel (p = 1.00) or neurological injury (p = 0.69), arterial hypertension (p = 1.00) and death (p = 1.00). No differences in the hemoglobin level at admission (p = 0.51) and discharge (p = 0.28) were noted. Three children treated with EPO and two controls did not require any RBC transfusion (p = 1.00). Median number of RBC transfusions needed by cases and controls was 2 (p = 0.52). CONCLUSION: Treatment with EPO did not reduce the number of RBC transfusions in D + HUS children. Assessment of EPO efficacy in D + HUS merits further studies.

Laboratory predictors of acute dialysis in hemolytic uremic syndrome.

BACKGROUND: Strict guidelines on use of dialysis in children with post-diarrheal hemolytic uremic syndrome (D + HUS) are lacking. This study investigated laboratory predictors of acute dialysis because they are more objective than clinical features. Added to this, given that urine output is also an objective parameter, its ability to predict dialysis requirements was also investigated. METHODS: Out of 153 D + HUS children reviewed, 88 received dialysis and 65 did not. Initial laboratory parameters and diuresis between both groups were analyzed. RESULTS: Dialyzed patients had higher creatinine, urea, alanine aminotransferase, hematocrit and leukocyte count; and lower sodium, bicarbonate, and pH compared to non-dialyzed ones. Serum creatinine was the only independent predictor (P = 0.003) of dialysis; therefore, its ability to predict dialysis was estimated on receiver operating characteristic (ROC) curve analysis and using the Acute Kidney Injury Network (AKIN) staging system. Area under the ROC curve was 0.92 (95% confidence interval [95%CI]: 0.83-1) with a creatinine cut-off of 1.25 mg/dL (sensitivity, 100%; specificity, 76.5%) for children <1 year, and 0.93 (95%CI: 0.88-0.98) with a threshold of 2 mg/dL (sensitivity, 91%; specificity, 87.5%) for older children. AKIN stage 3 at admission predicted dialysis with a sensitivity of 92% and specificity of 84.2%. Urine output had the highest accuracy for dialysis prediction (sensitivity, 100%; specificity, 95.3%). CONCLUSIONS: Initial serum creatinine concentration was the best laboratory predictor of dialysis, but the first 24 h diuresis was even better for this purpose. But, given that serum creatinine is an immediate available parameter, the cut-offs identified may label D + HUS children who will probably need dialysis, prompting early referral to centers able to provide dialysis.

Nephrotic syndrome due to immunoglobulin M mesangial glomerulonephritis preceding juvenile idiopathic arthritis.

The association between nephrotic syndrome and juvenile idiopathic arthritis have rarely been described in pediatric patients. We report a child with steroid-responsive nephrotic syndrome, with frequent relapses, who presented with a new relapse of nephrotic syndrome associated with arthritis and uveitis at 21 months in remission after treatment with chlorambucil. Juvenile idiopathic arthritis was diagnosed and kidney biopsy examination showed mesangial glomerulonephritis with immunoglobulin M deposits. To our knowledge, only 2 cases of nephrotic syndrome preceding juvenile idiopathic arthritis have been reported, one without histopathology assessment and the other with minimal change disease. Although mesangial glomerulonephritis with nephrotic syndrome and juvenile idiopathic arthritis could have been coincidental, the immune pathogenic mechanism accepted for both diseases suggests they could be related.

Impact of platelet transfusions in children with post-diarrheal hemolytic uremic syndrome.

BACKGROUND: Platelet transfusions should be avoided in children with post-diarrheal hemolytic uremic syndrome (D + HUS) because they might increase microthrombi formation, thereby aggravating the disease. As this possibility has not yet been explored, we investigated whether platelet transfusion in patients with D + HUS would lead to a worse disease course compared to that in patients who did not receive platelet transfusion. METHODS: This was a case-control study in which data from D + HUS children who received platelet transfusions (cases, n = 23) and those who did not (controls, n = 54) were retrospectively reviewed and compared. RESULTS: Both patient groups were similar in age (p = 0.3), gender (p = 0.53), weight (p = 0.86), height (p = 0.45), prior use of non-steroidal anti-inflammatory drugs (p = 0.59) or antibiotics (p = 0.45) and presence of dehydration at admission (p = 0.79). The two groups also did not differ in initial leukocyte count (p = 0.98), hematocrit (p = 0.44) and sodium (p = 0.11) and alanine aminotransferase levels (p = 0.11). During hospitalization, dialysis duration (p = 0.08), number of erythrocyte transfusions (p = 0.2), serum creatinine peak (p = 0.22), presence of severe bowel (p = 0.43) or neurologic (p = 0.97) injury, arterial hypertension (p = 0.71), need for intensive care (p = 0.33) and death (p = 1.00) were also comparable. CONCLUSION: Our findings suggest that platelet transfusion does not aggravate the course of the disease. Conversely, no hemorrhagic complications were observed in the group of patients who did not receive a platelet transfusion. Until these observations are confirmed by further studies, the benefits and risk of platelet transfusion should be thoughtfully balanced on an individual case basis.

Dehydration at admission increased the need for dialysis in hemolytic uremic syndrome children.

BACKGROUND: Oligoanuric forms of postdiarrheal hemolytic uremic syndrome (D+ HUS) usually have more severe acute stage and higher risk of chronic sequelae than nonoligoanuric forms. During the diarrheal phase, gastrointestinal losses could lead to dehydration with pre-renal injury enhancing the risk of oligoanuric D+ HUS. Furthermore, it had been shown that intravenous volume expansion during the prodromal phase could decrease the frequency of oligoanuric renal failure. Thus, we performed this retrospective study to determine whether dehydration on admission is associated with increased need for dialysis in D+ HUS patients. CASE-DIAGNOSIS/TREATMENT: Data from 137 children was reviewed, which were divided into two groups according to their hydration status at admission: normohydrated (n = 86) and dehydrated (n = 51). Laboratory parameters of the dehydrated patients reflected expected deteriorations (higher urea, higher hematocrit and lower sodium, bicarbonate, and pH) than normohydrated ones. Likewise, the dehydrated group had a higher rate of vomiting and need for dialysis (70.6 versus 40.7 %, p = 0.0007). CONCLUSIONS: Our data suggests that dehydration at hospital admission might represent a concomitant factor aggravating the intrinsic renal disease in D+ HUS patients increasing the need for dialysis. Therefore, the early recognition of patients at risk of D+ HUS is encouraged to guarantee a well-hydrated status.

Determination of urinary bicarbonate with the Henderson-Hasselbalch equation. Comparison using two different methods.

The determination of urinary bicarbonate with the Henderson-Hasselbalch equation was compared using two methods: (1) correcting the pK in every urine sample according to ionic strength and using the solubility constant of CO2 in urine (alpha=0.0309) and (2) using a fixed pK value (6.1) and a CO2 solubility constant of 0.0301, which we use to calculate blood bicarbonate. Nine patients were studied and 29 determinations were performed. A high correlation was found between the methods (r=0.99). Bicarbonate calculated with corrected pK was 24.3+/-6.6 mEq/l (95% confidence interval 11.4-37.2) and bicarbonate calculated with pK fixed at 6.1 was 25.6+/-6.6 mEq/l (95% confidence interval 12.7-38.5). For each urine sample, the delta bicarbonate was calculated as the difference between the bicarbonate obtained with pK at 6.1 minus that obtained with the corrected pK (mean 1.25, standard error 0.83, P=0.15). This indicates that the difference between the methods was not significant. No difference was found whether pK was corrected or fixed (6.1). Therefore, our results suggest that it is valid to take the value shown by the equipment for blood gas determination as the urinary bicarbonate value. This would allow the rapid and accurate determination of urinary bicarbonate in patients with hyperchloremic acidosis, especially those with renal tubular acidosis.